Graphic calculator



Jan. 27, 1948. F, DURAND VGRAPHIC CALCULATOR Filed March 22, 1945 @Q @QLs llt l Patented Jan. 27, 1948 UNITED STATES PATENT OFFICEApplicationMarch 22, 1945, Serial No. 584,104 In Switzerland March 23,1944 9 Claims. (Cl. 235-70) The present invention relates to a graphiccalculator composed of two scale-carrying elements capable of relativelymoving towards each other in such a manner that the scales always remainparallel, and of a sliding frame, its index always covering all scalesof the two-scale carrying elements at the same angle, the sliding framebeing provided with a coupling device, by means of which it can becoupled with the element carrying the multiplicand and dividend scalesin each of its positions, whereby the element carrying the multiplierandthe divisor-scales is provided with two detentions for the slidingframe, arranged in such a manner that the index of the sliding framecovers one of the terminal scale- .strokes of the multiplier anddivisor-scales, when 1 the sliding frame is brought to one of thesedetentions.

The sketch illustrates an embodiment of the graphic calculator, by wayof example.

Fig. l represents a front View of a slide-rule;

Fig. 2 shows a front-view ci the left hand end of the body of theslide-rule, on a larger scale;

Fig. 3 is a top plan View thereof;

Fig. 4 is a section on the line lis-d of Fig. 2;

Fig. 5 is a horizontal section on the line 5-5 of Fig. 2;

6 is a iront view of the sliding frame or runner on'an enlarged scale;

Fig. '7 is a top plan View thereof;

Fig. 8 is a section on the line 8-8 of Fig. 6;

Fig. 9 is a section on the line 9 9, Fig. 6.

Fig. l0 is a front elevation of the other right hand end portion of thebody of the slide-rule on an enlarged scale;

Fig. l1 is a top plan View thereof;

Fig. 12 is a section on the line IZ--IZZv of Fig. i

Fig. 13 is a section on the line I3-I3 of Fig.

The element carrying the multiplierand the divisor-scales, subsequentlydesignated as the body of the slide-rule, is composed of two bars i and2, attached to the terminal parts 3 and li by screws, and kept at acertain distance from each other by means of these terminal parts. Thesebars i and 2 are provided, on their surfaces facing each other withguides for a slider 5, movably arranged between these surfaces, andwhich forms the element carrying the multiplicandand dividend-scales.The terminal parts 3 and 4 form the stops for a movable, box-likesliding frame 5, lalso called cursor or runner, and shiftable .betweenthem on the body of the slide-rule. The multiplierand divisor-scales areapplied to the bars I and 2 in such a manner that their zero lines arelocated on the right hand edge of the stop 3. The stop 3 is provided onits front and back with a cut-out extending over the entire width of theslider 5, and opening in that edge of stop 3 which is directed towardsthe sliding frame 5. A transparent plate 'I is set into this cutout, itsbevelled edge 'I' serving as an index and being in exact alinement withthe zero lines of all scales applied to the bars I and 2. The slidingframe 5 is provided, on its front and back, with cut-outs, eachextending over the entire height of the scales of both the bars I and 2,and of the slider 5, there being an opening in that edge of the runnerwhich is directed towards the stop 3, a transparent plate 8 being setinto this cut-out with its bevelled edge 8' forming an index. If thesliding frame 6 is pushed on to the limit of its travel formed by theterminal part 3, this edge 8 registers with the initial division linesof the scales applied to the bars I and 2. The sliding frame 6 is,furthermore, provided on its front and back with additional cut-outs 9each of which is bridged by a spring-steel-plate I5 attached to thesliding frame 6, and having a width slightly less than that of theslider 5. A pad II made of rubber, leather, etc., is attached to theinner face of each steel-plate I EL If these steel-plates I0 are exedtoward each other, the pads II are pressed against the slider 5, wherebythis slider 5 is coupled with the sliding frame and, in this manner, theslider 5 is shiftable, together with the sliding frame 6. If thesteelplates are released, the pads II are lifted off the slider 5, dueto the resiliency of the plates, whereby this slider is freed from thesliding frame G, and remains stationary in case of a shifting movementof the sliding frame. lThe end division lines of the multiplieranddivisor-scales arranged on the bars I and 2 are positioned in such amanner that. when the sliding frame 5 is brought to the limit of itstravel formed by the stop 4, they are in register with the edge 8'serving as an index.

On the upwardly directed face of the bar I a scale Zil is provided, itszero-point being located in the same plane as the zero lines of thescales fixed up on the front faces of bars I and 2. In order to be ableto read this scale 20, a out-out is provided on the sliding frame 5opening in the direction of the terminal part 3, and a transparent plateI3 is set into this cut-out, whose bevelled edge I3 serves as an indexfor the scale. Adjoining the bevelled edge I3' serving as an index, aVernier-division I4 is provided on the plate I3, enabling a more precisereading of the scale. A metrical scale and an inch-divisioned scale maybe provided side by side on the top face of bar I, or a metrical scalealone may be arranged on the top surface of the bar l, and aninch-divisioned scale on the bottom surface of the bar 2. The edge I5 ofthe terminal part 3 corresponding to the zero-point of the scale, andthe edge I6 of the sliding frame 6 corresponding to the bevel edge indexI3' permit the use of the slide rule in a similar manner to that of theslidegauge. Inasmuch as, for measuring a length the edges I5 and I 6 ofthe terminal part 3 and of the sliding frame 6 are used, the lengthscale or scales might also be arranged on the front or back of the bodyof the slide-rule and be read by means of the edges l' and 8 of the stop3 and the sliding frame, so that a separate window on the outer side ofthe sliding frame S would not be required.

If a multiplication, a b, is to be carried out by means of theslide-rule, the sliding frame 6 is adjusted in such a manner that theindex edge 8' on 'the multiplicand-scale of the slider 5 lies above thevalue a, Subsequently, the sliding frame 5 and the slider 5 are coupledwith each other by pressing the steel-plates I together with the pads II gripping the slider 5, and in this coupled condition the slider 5 andrunner G are shifted together until `the runner strikes the stop 3,corresponding to the zero line of the multiplierscale of the body. Thenthe coupling of the sliding frame 6 and of the slider 5 is released, andthe sliding frame 5 alone is dislodged, until the edge 8 lies above b onthe multiplier-scale of the body, and by means of the edge 8 .the valueon the multiplicand-scale of the slider 5 is read as the product of theoperation. In order to carry out a division, a divided by "b, the edge 8of the sliding frame 6 is positioned above a on the dividend-scale ofthe slider, the sliding frame and the slider are coupled and moved inthis coupled condition, in such a manner that the edge 8' lies above bon the divisor-scale of the body,r and the result or quotient is readofi on the dividend-scale of the slider, by means of the edge l of thetransparent plate 1 in the window of the terminal part 3.

The graphic calculator, according to the present invention oersconsiderable advantages as compared with the slide-rules andslide-disks, so far known, i. e. (l) The body offers more space forapplication of the multiplierand divisorscales than the slides on whichthese'scales were applied heretofore.

(2) If the result of a multiplication is to be used as a multiplicandfor the next calculation, primarily the zero divisions of themultiplierscales must be positioned in register with this multiplicand.When using this slide-rule, this is done by pushing the sliding frame,while coupled with the slider, to the stop at the respective end of themultiplierand divisor-scales, without any attention whatever being paidto the scales. If the result of a division is to be used as a dividendfor the next calculation, the index 8' of the sliding frame 6 must' rstbe positioned in register with this dividend on the slider 5. This isdone by pushing the sliding frame, while uncoupled, from the slider tothe detention located at the respective end of the multiplieranddivisorscales. Also in this case, no attention must be paid to thescales.

These preliminary regulations of the slide-rule are eiected in a mostsimple, rapid, and precise manner, whereby the correct adjustment is tolmultiply a result with 10 the sliding frame,

i while uncoupled from the slider, is pushed then to the respectivestop. This movement against the kstop automatically effects a preciseadjustment, and this adjustment can be carried out, without-paying anyattention to the scales. The result can be brought Within to the rangeof the scales in a most simple, rapid and precise manner.

(4) inasmuch as the logarithmic scales of r2, m3, sin cos tan x, cot loglog :c, and of other functions are indicated in the usual manner on thebody, the values of the root of zu, the cuberoot of sin 1:, cos tan cotlog log and of other functions can be read orf on the logarithmic scale:c of 'the body. Inasmuch as multiplications and divisions arecalculated by means of this logarithmic scale a: of the body, it ispossible, in the course of a lcontinuous calculation, to directlymultiply with and divide by root of 11:, cube-root of r, sin x, cos x,tan cot log log m, and other functions, i. e. all logarithmicI scales ofthe body can be employed directly as a multiplier, or as a divisor. Theworking possibilities are thereby considerably simplified.

I claim:

l. A slide rule, comprising a body, a slide movably supported relativelyto the body and accessible from opposite sides of the body over itsentire length presented between the ends of the body, a sliding frame onthe body, and means on the frame for frictionally connecting said frameto said slide at any selectively determined point or said slide locatedbetween the ends of the body.

2. A slide rule, as set forth in claim 1, including a body assembled ofparallel bars and metal stop elements iiXed to said bars in such manneras to maintain them in parallel relation over their entire length, aslide movable between said bars beyond the stop elements, a framemovable on said bars and on said slide between the stop elements, andmeans carried by said frame adapted for engaging opposite sides of saidslide for coupling said frame with said slide at any selectivelydetermined point of saidrslide between said stop elements.

3. A slide rule, comprising a body formed o1' parallel bars, stop'elements xed to the ends of the bars and adapted to hold the bars inspaced parallel relation, the inner edge of one of said elements beingdisposed in registration with zero lines of gradations applied to saidbars, one of said stop Velements having a cut-out portion, a glass plateprovided with a beveled edge inserted in said cut-out portion in suchmanner that the beveled edge of said glass plate is in alinement withthose edge portions of the stop element which coincide with zerogradations on the bars. a slide between said bars and readable over itsentire length on opposite sides, a frame slidable relatively to saidbars and slide, and means on said frame for frictionally coupling saidframe with said slide by engagement with opposite sides of said slide,said coupling .means for the frame being operable on said slide on anyselectively determined point of said slide presented between the stopelements of said body.

4. A slide rule, comprising a body consisting of parallel bars, stopelements fixed to the ends of said bars and adapted to maintain saidbars in spaced parallel relation immovable relatively to each other, aslide movably supported in the space between and by said bars, a frameslidable on said bars between said stop elements and relatively to theslide, said frame having face portions on opposite sides of said barsand slide, and pressure plates normally spaced from said slide carriedby each of the face portions of the frame and depressible intoengagement with said slide on opposite faces thereof for coupling saidframe with said slide at any selectively determined point of said slidepresented between the stop elements cf said bars.

5. In a slide rule, the combination of a pair of bars, stop elementssecured to the end of the bars and adapted to maintain them in fixedspaced parallel relation, a slide movably supported between and by saidbars, a frame slidably supported relatively to said bars and said slideand having face portions on opposite sides of said bars and slide, saidface portions being provided with cut-outs, plates on both sides of theframe bridging said cut-outs, said plates being normally spaced from theopposite faces of said slide and being in registry with said slide, saidplates being depressible into engagement with opposite faces of theslide for coupling said frame to said slide for conjoint movement ofsaid slide and frame relatively to the bars.

6. A slide rule, as set forth in claim 5, including pads on the platesand facing opposite sides of the slide for engagement with said oppositefaces of the slide upon manual depression of the plates in directiontowards said opposite faces.

7. In a slide rule, the combination of a pair of bars, stop elements onsaid bars adapted to hold them in xed spaced parallel relation, a slidemovably supported between and by said bars and movable beyond each ofsaid stop elements, a frame slidable relatively to said bars and slide,means for frictionally coupling said frame to said slide at anyselectively determined point of said slide between said stop elements,one of said stop elements having an index line in alinement with an edgeof said stop element, an index line carrier on said frame adapted forabutment with said stop element in a position in which the index line onthe carrier of the frame abuts the index line of the carrier on the stopelement.

8. A slide rule, comprising in combination,

a pair of bars, stop elements secured to the ends of said bars formaintaining them in xed parallel relation, said bars being provided withgradations terminating at one end at a distance from the said stopelements, a slide movably support by and between said bars, a framemovable on said bars and on said slide, means for frictionally couplingsaid frame with said slide at any selectively determined point of saidslide presented between said stop elements, an index carrier supportedby said frame and having an index line, the index line of said framebeing in registry with the end line of the gradations on said bars whensaid frame is in engagement with the respective stop element on thebars.

9. A slide rule, comprising in combination, a pair of bars, stopelements secured to said bars and adapted to maintain them in fixedparallel relation, a slide movably supported by and between said barsand movable beyond said stop elements, one of said stop elements beingprovided with a cut-out, a glass plate inserted in said cut-out inposition over the space between said bar-s through which the slide ismovable, the bars having gradation lines, the edge of said stop elementcoinciding with the zero division of said gradation lines, the glassplate in the stop element having a bevel edge in alinement with the edgeportions of said stop element, a frame slidable relatively to said barsand slide and supported thereby, means for frictionally coupling saidframe to said slide at any selectively determined point of said slidepresented between the stop elements of the body, said frame having faceportions on opposite sides of said bars and slide, cut-out portions inthe opposite sides of said frame and extending over the width fof thecombined bars and slide, a glass plate inserted in each of saidcut-outs, said plate having a bevel edge adapted to serve as an indexfor the position of the frame relatively to said bars and slide, andadapted when the frame is in engagement with one stop element of thebody to overlie the zero line of gradations on the bars, and adaptedwhen in engagement with the opposite stop element to overlie theopposite end division lines of the series of gradations on the bars.

FRANCOIS DURAND.

REFERENCES 4CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,461.975 Eaton et al. July 17,1923 2,138,879 Poole Dec. 6, 1938

